If you are a SPED teacher and teach students at different levels, you have two options.
You can split your class into groups according to students' level and add another class. This option will let you choose a grade level for each group of students you have. Students will be able to take the placement test of their grade, and the data in your teacher account will be more representative due to the levels of the students you teach.
You can keep students in one class, select the grade that would fit best and customize any student's curriculum individually. You can always assign any student a certain topic or module from any grade you need.
In your teacher’s account, go to the Reports section and select Weekly Dashboard to view the list of your students. Click on a certain student to see his/her current progress and assignment details.
By switching to "Assignments/All topics" you will see the entire Happy Numbers curriculum, where you'll be able to choose a grade and customize the number of lessons assigned to this particular student by ticking off/picking up the right Modules for your students. The topics selected will be displayed in 'Assigned Topics'.